1. Technical Field
The present invention relates to an optical device. More particularly, the present invention relates to an optical device including phasors.
2. Related Art
A depolarization plate obtained by laminating three wavelength plates having a predetermined phase difference and an in-plane azimuthal angle has been known as disclosed, for example, in Japanese Patent Application Publication No. 2006-113123. This depolarization plate functions as a ¼ wavelength plate in the wideband wavelength range between 400 nm and 700 nm. Moreover, there has been known a depolarization plate that is divided into two portions by a border line passing through the center of the depolarization plate, in which one side of the depolarization plate is a ½ wavelength plate an optical axis of which is parallel or perpendicular to the border line and the other side is a ½ wavelength plate an optical axis of which has an angle with the border line of 45 degrees, as disclosed, for example, in Japanese Patent No. 2995989.
Since the depolarization plate disclosed in Japanese Patent Application Publication No. 2006-113123 converts a ray of linearly-polarized light into a ray of circularly-polarized light (or elliptically-polarized light), it is impossible to acquire light obtained by scrambling a polarized component of the linearly-polarized light. Moreover, in the technique of Japanese Patent No. 2995989, it is impossible to obtain depolarized light on the whole face perpendicular to a direction in which light travels.